#include <sys/types.h>
#include <iostream>
#include <cstdint>
#include <cstring>
#include <fcntl.h>
#include <vector>

using namespace std;

class A
{
private:
    // const int a = 10;
    enum
    {
        a = 10
    };
    int arr[a];

public:
    void show() { cout << a << endl; }
    void edit() { /*a = 20;*/ }
};

int main()
{
    vector<int8_t> list1 = {1, 2, 3};

    list1.begin() = list1.end();

    vector<int8_t> list2(10, 2);

    list2.insert(list2.end(), 1);

    A a;
    a.show();
    a.edit();
    a.show();
    return 0;
}
